The various wireless services that are currently receivable in a vehicle include radio, mobile wireless telephone, global positioning signals, CB radio, etc. Each of these wireless services requires an antenna optimized specifically for the particular frequency range. If several of these wireless services are required in one motor vehicle, the number of antennas required on the vehicle increases.
There have been various attempts to reduce the number of antennas required on a vehicle by using multi-band antennas, which may be operated in various frequency ranges. Then different wireless services are received over a single antenna.
In addition, it is conventional that antenna elements or a multi-band antenna may be integrated into the body of the vehicle.
Such a multi-band antenna may be integrated into the body of the vehicle as a disk antenna, for example, and may be provided for reception of AM radio, FM radio, and mobile wireless telephone, e.g., according to the GSM standard (Global System for Mobile Communications), as described in German Published Patent Document No. 297 16 979.
With such disk antennas, however, there is the problem that they are located within the visibility range of the driver and/or front passenger of the vehicle, and a large portion of the power they deliver is delivered into the interior of the vehicle due to the configuration. Another problem is that vehicle windows today are constructed with a metallized layer. However, this layer interferes with the directional diagrams of such disk antennas.
It is also conventional that antenna elements may be integrated into the interior mirror of a vehicle, as discussed in European Patent Application No. 0 821 429, for example. It is discussed in U.S. Pat. No. 5,682,168 that antenna elements may be integrated into the A-pillar or into braces of the vehicle. It is discussed in German Published Patent Application No. 197 30 173 that antenna elements may be integrated into the fender, doors, and roofs of the vehicle. In addition, it is discussed in German Patent No. 196 36 584 that antenna structures may be integrated into the bumpers of vehicles.